Evaluation of Reducing Ability and Antioxidant Activity of Fruit Pomace Extracts by Spectrophotometric and Electrochemical Methods

Table 4

Characterization of the main compounds of the grape pomace extract using their spectral characteristic in HPLC-DAD-MS.

Peak	Rt/min	Mode of ionization [M+H]^+/[M−H]^−	Fragments MS^2	UV-Vis max	Compound
Anthocyanins
1	10.01	465/—	303	277, 526	Delphinidin 3-O-glucoside
2	12.25	595/—	449, 287	280, 520	Cyanidin-3-O-glucoside
5	16.98	—/493	311	278, 528	Malvidin 3-O-glucoside
6	20.10	479/−	317	278, 527	Petunidin 3-O-glucoside
7	21.42	—	—	—	Unknown
8	24.87	—	—	—	Unknown
9	25.32	—	—	—	Unknown
10	26.91	—	—	—	Unknown
11	29.53	—	—	—	Unknown
12	31.53	—/609	301	520	Peonidin 3-O-p-coumaroylglucoside
13	32.54				Unknown
Phenolic acids
14	5.8	—/169	125, 107, 97, 79	280	Gallic acid
15	12.7	—/153	109	280	Protocatechuic acid
16	18.0	—/137	93	280	p-Hydroxybenzoic acid
17	20.8	—/295	163	280	Coutaric acid
18	23.4	—/179	135	280	Caffeic acid
19	25.4	—/289	245	280	Epicatechin
20	25.7	—/197	153/182	280	Syringic acid
21	31.0	—/163	119	230, 310	p-Coumaric acid
22	31.0	—/223	164/208	280	Sinapic acid
23	32.5	—/193	134	280	Ferulic acid
Flavanols
24	17.5	—/289	245	244, 276	(+)-Catechin
25	45.2	—/463	300, 255, 151	256, 354	Quercetin-3-O-glucoside
26	47.3	—/609	300	254, 353	Quercetin-3-O-rutinoside
27	48.5	—/447	284, 255, 227	265, 346	Kaempferol-3-O-glucoside
28	55.7	—/301	301, 151	254, 371	Quercetin